Summary: INTRODUCTION
Located about 80 km (50 miles) northeast of Eureka and
121 km (75 miles) southeast of Elko (Fig. 1), the Bald Moun-
tain district is situated in the southernmost part of the Ruby
Range, a metamorphic core complex (Rigby, 1960). Histori-
cally, the Bald Mountain district has produced silver, antimony,
lead, tungsten, copper and placer gold (Hitchborn, 1996). Cur-
rently, this district is being mined as a series of open pits to
exploit fissure-hosted and disseminated gold. These deposits
have some geochemical characteristics of Carlin-type gold
deposits, such as elevated levels of thallium, arsenic, and bar-
ium in addition to gold. However, they also have characteristics
that are not clearly Carlin-type, such as elevated bismuth val-
ues. It is not clear what kind of deposit Bald Mountain is, but it
does represent fossil hydrothermal systems of some sort that
ultimately deposited gold. The study described here was initi-
ated to determine if low-temperature thermochronology and
stable isotope techniques could be used to identify the location
of thermal anomalies and fluid flow at Bald Mountain.
Thermal and chemical profiling of the